Welcome to my astronomy blog, I dedicate myself to the simplest form of amateur astronomy which requires only portable equipments.

Thursday, April 30, 2009

Tele Vue Ranger transformed

The focusers side by side, they're with similar length. The JMI has much shorter travel due to the lack of that sliding draw tube, the fine focusing range is not differ by much. However, you can remove that extension tube (1.5" long) for more in-travel for the NGF-S.

This is the custom made adapter, with perhaps 1-2mm more female thread, it will look better. Anyway, it works.

Focuser attached, very elegant and the Ranger has a new life. Shall I call it a Pro-ger?

Last night, I tried to put my 2" mirror diagonal there, and as expected, with the extension tube of the NGF-S, it couldn't reach focus, I've to slide the diagonal a little bit outside. With the extension tube in place, it could not too. Anyway, it's my design since I wanted to retain the most in-travel. By keeping the diagonal a little bit out from completely flushed in, it's secure enough. All of my eyepieces and barlows work in this way, slide out a little bit and that's it. Maybe a 2" filter thread extension tube would serve as a more elegant draw tube for quick focusing, but it's all later work.

The transformed OTA is shorter than before, and a little bit more heavy as expected. The focuser could be easily removed and re-orientated. That would enable it to sneak into my Fast Pack 350 without problem. Excellent portability.

Tomorrow if the weather allows, I shall try to use it on the sun with my Solarmax 40/BF10, that's going to replace my Borg 45ED II and I shall also try it out with a 0.5x binoviewer corrector.

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So before the sunshine comes, I try to put everything together and point it to terrestial target to test the focus travel:-